Conditions for Running the DTC

WARNING: This page is about a different variant/trim than selected.

Before the ECM can report DTC P0449 failed, DTC P0451 must run and pass.
The engine speed is greater than 80 RPM.
The ignition voltage is between 10-18 volts.
The ECM has commanded the EVAP canister vent valve ON and OFF at least once during the ignition cycle.
The DTCs runs continuously once the above conditions are met.